Diaphragm pump



Jan. 5, 1965 G. VAN NEDERYNEN DIAPHRAGM PUMP 4 Sheets-Sheet 1 Filed Sept. 27, 1962 7 INVENTOR GERR/T VANNEDERYNE/V ATTORNEY 1965 G. VAN NEDERYNEN 3,164,101

DIAPHRAGM PUMP Filed Sept. 27, 1962 4 h et 2 INVENTOR T WIVNEDERWE/V G. 'AN NEDERYNEN Jan. 5, I965 DIAPHRAGM PUMP 4 Sheets-$heet 3 Filed Sept. 27, 1962 FIG. 5

INVENTOR GERR/T VAN IVEDERY/VE/V AT RNEY United States Patent Ofiice 3,164,101 Patented Jan. 5, 1965 3,164,101 DIAPHRAGM PUMP Gerrit Van Nederynen, Sayre, Pa., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Sept. 27, 1962, Ser. No. 226,666 19 Claims. (U. 103-15 2) motion of the motors into reciprocating motion of the diaphragm connecting rod. Usually the motors are'designed to operate at a relatively constant speed so that the driving force imparted to the diaphragm connecting rod during each stroke of the latter varies from a minimum value, equal to the motor torque divided by the crank throw, to infinity depending upon the angular position of the crank. However, the force required during each stroke of the diaphragm connecting rod to displace the fluid being pumped through the discharge line of the pump, after the fluid has been accelerated, is constant. Since the constant force necessary to pump the fluid during each stroke or actuation of the diaphragm should never exceed the minimum force that the crank is capable of transmitting to the diaphragm connecting rod, the

pumps are designed to utilize the minimum crank force phragm pump capable of being easily adjusted to various pumping requirements.

A further object of the present invention is to provide in a diaphragm pump a diaphragm actuating means of relatively simple construction.

A still further object of this invention is to provide, in a diaphragm pump, a safety device to prevent damage to the pump or motor in the event of overloading or jamming of the pump.

The present invention, therefore, contemplates a novel diaphragm pump comprising at least one diaphragm fixedly secured at its periphery in a casing forming an actuating chamber. Valved inlet and outlet means are connected to the casing to provide for passage of fluid to be pumped into and out of the working chamber upon actuation of the diaphragm.

A fluid actuating-means is provided to effect actuation of the diaphragm. The fluid actuating means includes a connecting rod suitably supported in the casing for reciprocation to cause actuation of the diaphragm alternately in one direction and then the opposite direction and thereby efiect pumping of the fluid to be pumped through the inlet and outlet connections. The connecting rod is constructed and arranged to extend coaxially through a piston chamber disposed adjacent to the actuating chamber formed by the diaphragm casing. A piston means is secured to the connecting rod and disposed for reciprocation in the piston chamber. A fluid pump, of the constant or variable displacement type, such as a gear or multi-vane type pump, is provided along with a valve control means to alternately supply high pressure fluid to opposite sides of the piston to thereby elfect reciprocation of the connecting rod.

The fluid pump is driven by direct connection, or through a simple speed reduction mechanism, to a prime mover, such as an electric motor or internal combustion engine.

A further feature of the present invention is a safety means constructed and arranged in cooperative relationship with the fluid pump to by-pass high pressure fluid around the piston cylinder in 'the event of overloading o jamming of the diaphragm pump.

In one embodiment of the invention the diaphragm pump comprises two diaphragms connected to opposite ends of a connecting rod with each diaphragm having suitable valved inlet and outlet means for providing flow of fluid to be pumped,

In another embodiment of the invention the diaphragm pump comprises a single diaphragm with suitable inlet and outlet means connected to communicate with the actuating chamber on each side of .the diaphragm so as to provide fluid discharge in each direction of actuation of the diaphragm.

In a further embodiment of the invention the diaphragm pump comprises a single diaphragm with inlet and oulet means connected to communicate with the actuating chamber only on one side of the diaphragm so, as to provide fluid discharge only in one direction of actuation of the diaphragm. In addition, mechanical means may be provided for biasing the diaphragm in the direction of the discharge stroke of the diaphragm.

The invention will be more fully understood from the following detailed description thereof when considered in connection with the accompanying drawings wherein several embodiments of the invention are illustrated by Way of example, and in which:

FIG. 1 is a sectional view of the diaphragm pump according to one embodiment of the present invention; 7

FIG. 2 is a view similar to FIG. 1 showing another operative position of the components of the diaphragm P p;

FIG. 3 is a transverse sectional view taken substantially along line 33 of FIG. 1 looking in the direction of the arrows;

FIG. 4 is a transverse sectional view taken substantially along line 44 of FIG. 1 looking in the direction of the arrows;

FIG. 5 is a view, partly in section, showing another embodiment of this invention; 7

FIG. 6 is a view, similar to FIG. 5, showing a still further embodiment of the present invention; and FIG. 7 is an enlarged fragmentary view, in cross section, of the control valve and safety device which form a part of this invention and are shown in FIGS. 1 and 2.

Referring now to the drawings and more specifically FIGS. 1 to 4, the reference numeral 10generally designates the diaphragm pump according to one embodiment of this invention. Diaphragm pump 10 comprises a pair of diaphragm pump subassemblies 11 and 11'A disposed in spaced parallel relationship to each other. Since the diaphragm pump sub-assemblies 11 and 11A are identical in construction, only the pump sub-assembly 11 shown to the left of the center line of the diaphragm pump assembly 10, as viewed in FIG. 1, will be described in detail, and like parts of diaphragm pump sub-assembly 11A will be given like reference numerals with the sufiix A. s

Diaphragm pump sub-assembly 11 comprises a housing 12 having two substantial dish-shaped parts joined together to define a chamber 13 in which is disposed a flexible diaphragm 14. Diaphragm 14 may be of conventional construction and is herein illustrated as con sisting of an annular flexible member 15 clamped along clamped in a fluid tight mannerbetween the two dishshaped housing parts by a plurality of circumferentially spaced bolts '19 sothat the diaphragm divides chamber 'ls'into a working or" pum ing chamber as and" an atmospheric chamber 21, the latter chamber being in communication with the ambient atmosphere through a port 22 in ,the wall of housing 12. To actuate the diaphragms' .lli'and 14A within chambers 13 and 13A, respectively,

thediaphr'agms 14 and 14A are secured to the opposite ends of a connecting rod 23 which is supported for recipi'ocation'in aligned bores 24 and 24A formed in the wall of housings l2 and 12A. The opposite end portions'of connecting rod 23 are of reduced diameter so as to pass through centrallylocatedholes' in disks i6 and 16A and are threaded to receive nuts 25 and 25A to secure each of thediaph'ra'gms to the connecting rod.

Introduction and discharge of fluid to be pumped into and from each of the diaphragm pump'sub-assemblies 11 and 11A is pro'vided forby conduits 25 and 26A which are connectedat one end to housings 12 and 12A, respectively, to communicate with the respective working chambers 21 and 26A of' the diaphragm pump subasse'mbli'es' 11 and 11A. The opposite end of each of the conduits 26 and 26A is connected to an inlet conduit 27 and'a 'dis'charge'conduit 28. A pair of check valves 29 and 29A0f conventional type, such as ball type che'ck'valves, is disposed in inlet conduit 27 adjacent conduits26 and 26A to control flow, of fluid to'be pumped into conduits 26 and 26A and the respective working chambersit! and'ZtlA'. A. pair of check valves and sive to actu'ation of diaphragms 14 and 34A 'toalternately 1 provide flow of fluid from inlet conduit 27 into one of the working chambers 20 orZtiA of the diaphragm pump sub-assemblies 1-1 and 11A and discharge fluid from the other Working chamber into discharge conduit 28.

Disposed between and suitably connected to. diaphragm pump sub-assemblies 11 andiilA is a fluid actuating means for eflecting reciprocation and hence the actuation-of diaphragms ld'an'd 14A. The fluid actuating means comprises a housing 32 which is constructed and ."arranged toprovide a cylindrical piston chamber 33 lo-' cated concentric witli'the longitudinal axis of connecting rod "23. 'A piston 34*of anysuitable construction is secured to-connecting-rod 2 3, substantially mid-way of its length, as by a pair or retaining rings 35. T 0 provide for alternate flow of fluid under pressure to the piston chamber 33; first on one side of piston 34 and then to the opposite side of the piston to effect reciprocation ofconnecting rodZd, a fluid pump 36, a control valve 37, and suitable passagewaysare provided in housing 32, as hereinafter m'orefully'described.

Fluid Pump I Fluid pump 36 may be of the constant or variable displacement type, such as 'a gear pump, or a multi-vane um For illustration purposes, fluid pump 36 is shown as a gear pump having two intermeshing gears 38 and 39 secured to shafts 4t and 41, respectively, for rotation. Gears 38I'and 39 are disposed in a pump chamber formed within housing 32 so as to dividethepump chamberinto a high pressure section 42 and a low pressure section 43.

A'prime mover (not-shown) such as an electric motor,

internal combustion engine or the like, is connected either directly or indirectly through a simple gear reduction mechanism (not shown) to shaft 4d and/or shaft 41 to rotatively drive the latter and thus rotate gears 33 and 39. Fluid pump 36 may also be a pressure compensated pump of the piston, gear or vane type. This type of pump is capable of sensing the output pressure of the fluid in high pressure section 42 and, as the pressure decreases, the pump automatically delivers a greater volume of fluid so that the work output remains substantially constant regardless of the output pressure or head against which the diaphragm pump assembly works.

C orztrol Valve As best shown in H6. 7, a control valve 37 for controlling flow of pressurized fluid from fluid pump 36 to piston chamber 33, is disposed within a bore 44 formed within the housing 32. between fluid pump 3% and piston chamber 313. Control valve 37 comprises an elongated cylindrical body 4 5 having a central portion 46 of enlarged diameter adapted to slidabiy engage the peripheral surface-of bore dd. The body 45 is of a length shorter tha n't'he length 'of bore 4-4 so as to permit axial slidable movement of body 45 within bore 44. Axial recesses 47 are provided in body 45 extending inwardly from the opposite ends of the body. A piston 48 is disposed to partly extend into each of the recesses 47 and a bore 4? arranged coaxial to and adjacent each of the ends of body 4-5. A spring 50 is disposed in each of the recesses 47 to bias each of the pistons 33 in a direction toward their associated bores d9 To provide the control valve 37 with rapid or snap action, the central portion 46 of body is provided with two annular, semiarcuate recesses 51 which are adapted to receive a portion of a ball 52. Ball 52 is disposed partly in a hole 53 and is biased by a spring 54 to engage recesses 51 in body 4-5 of the control valve.

Fluid Flow Passageways To provide for flow or pressurized fluid from the high pressure section 42 of fluid pump as, a passageway 55 is provided which extends from communication with high pressure section 42 to bore 4- 5 and into communication with recesses 51, With the control valve in the position as shown in FIG. 1, a passageway 56. formed in housing 32, is in communication at one end with passageway 55, through one of the annular recesses 53, and at the opposite end with piston chamber 33 to the right of piston 34 as viewed in FIG. 1. A passageway 57, similar to passageway 56, is provided, which passageway, in the position of control valve 37 as shown in 'FIG. 1, communicates at one end with piston chamber '33 to the left of piston 34 as viewed in PEG. 1 and way of passageway do to force piston 34 in a direction to the left as'viewed in FIG. 1, while passageway 57 conducts low pressure fluid, as piston S t-moves in a direction to the left out of chamber 33, in-to bore 34. To return this low pressure fluid to the low pressure section 43 of fluid pump 36, a return conduit 58 is disposed to communicate at one end with bore 44 and at the opposite end with low pressure section 53. A second' return conduit sa, similar to conduit 53, is provided to communicate at one end with low pressure section 43 of fluid pump 3% and at the other end with bore 44 so that, when control valve 37 is in a position to the right of that shown inFIG. 1, spent pressurized fluid in chamber 33 to the right of piston 34 will be conducted from the chamber through passageway as, bore 44 and conduit 59, to low pressure section 43.

. To provide for automatic actuation of control valve 37, tubular piston members 6% are disposed at opposite ends of piston chamber 33 in openings 61 which are formed in housing 32 coaxial with chamber 33. Each of the piston members 6a is provided with a reduced diameter portion 62 which is slidably receivable in opening 61, and an enlarged portion 63 which is slidably receivable in a counterbored portion of opening 61. The adjacent peripheral surfaces of the piston member 60 and opening 61 between the respective shoulders formed by the reduced diameter portion 62 of piston member 60 and the counterbor ed portion of opening 61 define therebetween an annular pressure chamber 64. To communicate each pressure chamber 64 with one of thebores 49, a passageway 65 is formed in housing 32. A retaining ring 66 is disposed in an annular groove formed in the periphery of the piston member 60 adjacent the reduced diameter end portion 62 to limit the movement of piston members 6t? inwardly toward the center of piston chamber 33. The opposite or outward movement of piston members 6%) is limited by the latters abutment against the wall of housing 12 and 12A. Piston members 6! function to compress the fluid entrapped in annular pressure chamber 64 and passageway 65, when the piston members are moved axially outwardly under the urging of piston 34 after contact of the latter against the piston members during the latter part of the stroke of piston 34.

In operation of the pump, piston members 60 cooperate with control valve 37 as follows: When the fluid in chamber'64and passageway 65 is pressurized by movement of piston member 6%, the fluid exerts a pressure against the end of piston 48 in a direction to compress spring 56. The pressure exerted on piston 48 compresses spring 50 until the energy stored in spring 5% is sufficienit to overcome the force exerted by ball 52, through spring 54, against the annular recess 51 in body 45 of control valve 37 and the slight frictional forces between control valve 37 and bore 44. When the energy stored in spring 5i) overcomes the force exerted by ball 52 against control valve 37 and the frictional forces resisting movement, spring 50 moves body 45 of. the control valve causing ball 52 to-be depressed against the tension of spring 54 and the body 45 to snap into the next adjacent recess 51 of the control valve to hold the latter in this other position. After control valve 37 has moved to a new position, the tubular piston member 6% is returned to its normal position under the urging of fluid pressure in chamber 64 as spring 50 forces piston 43 back into bore 49.

The pressurized fluid for fluid pump 36 is introduced into housing 32 through a flller port 7 (9. Since the above described fluid actuating means which includes pump 36, is a closed cycle system where the fluid is recirculated to fluid pump. 36 after it performs work by actuating piston 34, the filler port 70 is closed by a plug 71 which may be removed to introduce make-up fluid into the actuating means to compensate for possible loss of fluid due to leakage. Low pressure. chamber 43 is vented to atmosphere by suitable means (not shown), such as by a vent hole in plug 71.

Fluid pump 36 may be provided with a reserve .fluid chamber (not shown) which communicates through a suitable passageway (not shown) with low pressure chamber-43 to provide a reserve of fluid .to compensate for' possible fluid loss during operation of the pump. The

.filler port 70 may be disposed to communicate with the reserve fluid chamber so that make-up fluid isintroduced Y initially into the latter. V

Operation 39 pumps fluid from high pressure section 42 into and to the right of piston 34 as viewed in FIGS. 1 and 2, and

through passageway 55. ,Assuming the control valve 37 is in the position shown in FIG. 1, pressurized fluid from passageway flows into and through passageway 56, via an annular recess 51 in body 45 of control valve 37. The pressurized fluid then flows from passageway 56 into piston chamber 33 to thereby force piston 34 to move to the left as viewed in- FIG. 1. The fluidlin piston chamber 33 to the left of piston 34 as viewed in FIG. 1 is forced by movement of'piston 34, through passageway 57 and thence into bore 44, via the annular chamber defined by the peripheral surface of the bore and the spaced outer surface of the reduced end portion of the valve body 45. From bore 44-, the low pressure or spent As the piston 34 approaches the end portion of its stroke to the left as viewed in FIG. 1, it impinges against tubular piston disposed in the left hand side of chamber 33. The tubular piston 60 under the urging .of piston 34 is moved to the left as viewed in FIG. 1. This movement of tubular piston 6% tends to compress fluid in chamber 64 and passageway 65, which fluid acts against the end of piston 48 in the left hand end of control valve 37 to move piston 48 axially against the tension of spring 5t; associated with piston. When, as previously described,

the force stored in spring 50 exceeds the force exerted upon the valve body 45 by the spring loaded ball 52 and the frictional forces resisting movement of the control valve, the control valve will snap to the right as viewed in FIG. 1, with the ball 52 being forced out of the recess 51 and into the next adjacent recess 51. This movement of control valve 37 in a direction to the right simultaneously seals passageway 55 from passageway 56 and brings the latter into communication with bore 44 and return conduit 59. In addition, such movement of control valve 37 simultaneously seals" passageway 57 from bore 44 and return conduit 58 and effects communication between passageway 55 and passageway 57. In this aforedescribed control valve position, pressurized fluid from high pressure section 42 flows into piston chamber 33 to the left of piston 34 as viewed in FIG. 1, via passageway 55, recess 51 and passageway 57. The flow of pressurized fluid into chamber 33, from passageway'57, forces the piston to move to therightas'viewed in FIG. 1 and into impingement with the tubular piston 60 disposed in the right hand side of piston chamber 33 as viewed inFIGS. 1 and 2. As shown in FIG. 2, piston 34 has already sufficiently moved piston 60 to cause fluid in chamber 64 and passageway 65 to effect movement of piston 48, in the right'hand end of the control valve, to the left as viewed-in FIGS. 1 and 2 and compression of spring 50 sufliciently to snap control valve 37 to the left. In this position of control valve 37, passageway 56 is again in communication with passageway 55 to provide flow of pressurized fluid into piston chamber 33 thereby effect movement of piston to the left as viewed in the figures. In the aforedescribed manner, piston 34 is reciprocated in piston chamber 33; and since the piston is secured as by key 35 to connecting rod 23, rod 23 is reciprocated. v

I Reciprocation of connecting rod 23, .actuates diaphragms 14 and 14A in their respective chambers 13 and 13A. As viewed in FIG. 1, movement of connectingrod 23 in a'direction to the left, forces diaphragm 14 to move to the left and thereby forces fluid to be pumped out of working chamber 20, through conduit 26, past ball valve 30, and into discharge conduit 28 for delivery to the point of use. I The pressure of the fluid in working chamber 20, as it is displaced by diaphragm 14, unseats ball valve 30. against the tension of its spring 31. Atthe same time, the fluid pressure assists spring 31 in holding ball valve 29 seated in a closed position. vSimultaneous with the movement of diaphragm 14, diaphragm 14A moves '2 to the left, as viewed in FIGS. 1 and 2, within atmospheric chamber MA. This movement or suction stroke,

draws fluid to be pumped into working chamber A,-

past ball valve 29A, and through conduit 26A from intake or supply conduit 27. Valve 30A, in discharge conduit 28, is seated in a closed position under the" urging of its spring 31 and the fluid pressure in discharge con duit 2%. Upon movement of Connecting rod 23 to the right as shown in FIG. 2,,diaphragm 14A is forced into Working chamber 29A to force the fluid to be pumped out of the working chamber, through conduit Z EA, past ball valve 38A, and into and through discharge conduit 28.

. Simultaneously, fluid to be pumped is drawn into working chamber 2% by movement of diaphragm 14 into atmospheric chamber 21. The fiuid'is drawn into working chamber 2% from fluid supply conduit .27, past vaiveffi and through conduit 26. Thus, reciprocation of connecting rod 23 actuates diaphragms 14 and 14A withintheir respectivehousings i2 and 12A so that each diaphragm,

ofpumpsub-assemblies l1 and 11A through check valves I 29, 39,. 2A and NA, is alternately charged with fluid to bepurnped through supply conduit 27 and displaces the charged fluid through discharge conduit .28. in addition,.a' relatively constantdischarge of fluid is achieved since as one pumpsub-assembly is being charged the other. is discharging pumped fluid.

Safety Device The diaphragm pump Iii may be provided with a safety means, as shown in FIGS. land 2, disposed be- I;

tween passageway and return conduit 58 torecirculate fluid in .the eventthe fluid pressure exceeds a predetermined pressure which would be a' value just below the capacityof the prime mover (not shown) driving fluid pump 36. As illustrated in FIGS. 1 and 2, the safety means may be an adjustable spring loaded regulating vaive '72. As best shown in FIG. 7, a bore 73 is provided in housing- '32 extending between passageway 55 and return conduit5 8. V Bore 73 has a counterbored portion 74 which extends fromretum conduit 58 to a point short of passagev/ay55 Abml YE-is disposed to normally rest against a seat formed at the juncture of bore 73 and counterbored portion 74 to seal passageway 55 from return conduit 58. Arradjustingmember, having a threaded body 7d and a reduced diameter stem portion '77,

. is receivable in a threaded bore in housing32 so that -stem -portion 7'7 extends coaxially within counterbor ed I portion 7530f bore '73. A spring 78 is disposed over stem portion '77 of the adjusting member and, at one end,

butts against ball75 and, at the opposite end, against a moved in or out of housing 3 2 to increase or decrease the tension of spring 73 and thereby adjust regulating'valve 72 for a selected predetermined pressure at which-ball V '35 will unseat.

i In theoperation of the regulating valve 72, ball 75 is normally seated to prevent by-pass. of high :,-pressure fluid to return conduit 58. However, if the discharge conduit 28 is accidentally closed, the designed maximum dischargef head is exceeded, or if the diaphragm pump 10 becomes.accidentally'jammed with contaminantsor other entrained matter in the fluid being pumped, which conditions will cause a build-up of pressure in passageway 55,

"ball '75 will unseat when the pressure in passage way ds exceedsa predetermined pressure as determined by ad- 'justmentof the tension of spring 7,3. 'VVith'ball '75 unseatedypassageway So'ds brought into communication with return conduit 55, thereby allowing fluid to flow from passageway 55 to conduit Sha'nd back to fluid pump 36. By recirculation of high pressure fluid back to'fiuid pump 36 through return conduit 58, high pres- "line 39, 'asindicated by the broken line arrows.

sure fluid by-passes piston chamber 33 so that operation of diaphragm pump 19 ceases and prevents damage to the prime mover (not shown) and/ or other components of the diaphragm pump.

In FIG. 5 is shown another embodiment of the diaphragm pump according to this invention. The diaphragm pump 89 illustrated in FIG. 5 differs from the embodiment shown in FIGS. 1 to 4 and 7 in that it is provided with only one diaphragm pump subassembly 81. The fluid actuating means, including connecting rod 23, piston 34, fluid pump 36, control valve 37, and a suitable prime mover (not shown), for eflecting actuation of diaphragm pump sub-assembly 81 is the same as described in the embodimerit of FIGS. 1 to 4 and 7, except that the fluid actuating means has been inverted merely to provide clearance for fluid connections to the diaphragm sub-assembly 81. In addition, the construction of the diaphragm is the same as diaphragms 14 or 14A of the previously described embodiment. Therefore in FIG. 5, component parts of diaphragm pump 8% corresponding to component parts of diaphragm pump 10 will be identified by the same reference numerals.

In diaphragm pump diaphragm 14 of diaphragm pump sub-assembly 31 divides the actuating chamber formed by housing 12 into two working or pumping chambers 82 and 83. A conduit 84 is connected to housing 12 so as to communicate with working chamber 82 and provide flow of fluid into and out of chamber 82. A conduit 35, similar to conduit 34, is connected to housing 12 so as to communicate with working chamber 83 and provide flow of fluid into and out of chamber 33. To supply fluid to be pumped from a suitable source thereof, a fluid supply line 85 is connected at one end to the source of fluid (not shown) and through branch lines 37 and 88 to con- .duits 84 and 85, respectively. To deliver pumped fluid to a point of use (not shown), a discharge line 89 is connected through branch lines 99 and 91 to conduits 84 and 85', respectively, and to the point of use (not shown). Check valves 92, 93, 4 and which may be of the ball type, as shown, are disposed in. branch lines 87, 83, W and 91, respectively, to alternately permit flow oi fluid into and from working chambers 82 and 83.

Each of the check valves 92, 93, 94 and 95 is biased in a closed position by a spring 95.

In operation of diaphragm pump 80, connecting rod 23 is reciprocated as described in the embodiment shown in FIGS. 1 to 4. Upon reciprocation of connecting rod 23, diaphragm 14 is actuated in housing 12 of diaphragm pump sub-assembly 81. When,.as shown in FIG. 5, diaphragm 14 is actuated from the broken line position to the position shown in solid lines, fluid in Working chamber 83 is forced therefrom, through conduit 85, past check valve 95 whichhas been unseated by the pressure of the fluid, and into 'and'through branch line 91 and discharge line 89, as indicated by the solid line arrows. Simultaneously, fluid is drawn from supply line 86, branch line 37, past check valve 92 which has been unseated by reason of the differential pressure across the ball of the check valve, and thence through conduit 84 into working chamber 82, as shown by the solid line arrows. Upon movement of diaphragm 14 from the solid line position as shown in FIG. 5 to .the broken line position, fluid drawn into working chamber 82, as above described, is forced through conduit 84, past check valve 94 which is forced open by the fluid pressure, and thence through branch line hit into discharge Simultaneously, fluid to be pumped is drawn into working chamber 83 through conduit 85, past check valve 93 which has been forced open by the differential pressure across the ball of the check valve, branch line 88, and supply line 85, as indicated by the broken line arrows. In the aforedescribed manner, fluidvis alternately drawn into and discharged from each of the working chambers 82. and 83 upon each reciprocation of piston 34.

In F16 6 is shown a still further embodiment of the 9 present invention which is similar to that shown in FIG. in that the diaphragm pump 100 has only one diaphragm pump sub-assembly 101. Diaphragm pump 100, however, differs from the embodiment shown in FIG-5 in that it has only one working or pumping chamber 102 instead of two, with the other chamber 103 formed by the diaphragm 14 being in communication with the atmosphere through a suitable port (not shown) in housing 12. Since there is only one working chamber 102, only one conduit 104 is 1:

connected to the housing and to a supply line 105 and discharge line 106. As shown in the previous embodiments, check valves 107 and 108, such as spring loaded ball valves, are disposed in supply line 105 and discharge line 106 to control flow of fluid alternately into and from working chamber 102 upon actuation of diaphragm 14.

Diaphragm pump 100 with a fluid pump 36 of the pressure compensated type provides a relatively slow discharge stroke and a relatively fast suction stroke by reason of the difference in pressure against which the diaphragm .must Work on suction and discharge strokes.

The diaphragm pump 100, shown in FIG. 6, may be provided with a spring 110 disposed around connecting rod 23 and between diaphragm 14 and housing 12.. Spring 110 permits utilization of more of the available fluid pump force by storing energy as it is compressed on the suction stroke and releasing that stored energy upon the discharge stroke and thereby providing a greater discharge pressure or head than is possible if the spring were omitted.

The diaphragm pump 100 operates in the same manner as described with respect to one of the diaphragm pump sub-assemblies shown in FIGS. 1 to 4 and therefore it is believed unnecessary to describe its operation. The component parts of diaphragm pump 100 corresponding to the same component parts as in the preceding embodiments have been identified by the same reference numerals.

It is, therefore, believed readily apparent that the present invention provides a diaphragm pump of greater efliciency than heretofore known diaphragm pumps since a substantially greater amount of the total output of the prime mover is utilized on the discharge stroke of the diaphragm. In effect this permits the use of a prime mover under theoretical conditions of about 37.5% less capacity for the same pump output requirements than diaphragm pumps of conventional construction. In addition the invention provides a diaphragm pump which is substantially smaller in size, weight and cheaper in cost than heretofore known pump of the diaphragm type. Furthermore, the diaphragm pump has an automatic safety device which prevents accidental damage to the diaphragm or diaphragms,

the prime mover, and other component parts, by pressures in excess of the designed maximum discharge pressure or head, jamming resulting from contaminants in the fluid being pumped, or unintentional closing of the discharge line.

The present invention also provides where a fluid pump of the pressure compensated type is employed, a diaphragm purnp capable of providing a substantially constant work output regardless of the output head or' pressure against which the pump must work. This type of diaphragm pump assembly is particularly well suited for application to portable pumpequipment where the output head may vary with the place of use.

Although several embodiments of the invention have been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. 'Various changes can be made in the arrangement of partssaid housing for conducting fluid to be pumped to' said housing,

(c) discharge means communicating with the interior of said housing for conducting pumped fluid out of said housing, and I a a j "(d) fluid actuating means for actuating said fluid displacement means within said housing to cause fluid to be drawn into said housing through said supply means and to force fluid from saidh'ousing through said discharge means,

(e) said fluid actuating means including (1) a fluid pump to provide fluid underpressure, "(2) a control mean responsive to fluid pressure for actuation from one position to another for controlling flow of fluid under pressure so as to effect actuating of said fluid displacement means and thereby alternately draw fluid to be pumped into said housing and discharge said fluid from the housing,

(3) means forming a fluid chamber, (4) passage means communicating said fluid chamber with said control means, and (5) piston means disposed for slidablernovement l in said fluid chamber and for engagement with said fluid actuating means and slidable movementto compress the fluid in said fluid chamber and thereby effect actuation of the control means from said one position to another.

2. A diaphragm pump comprising (a) at least one diaphragm pumping means including a diaphragm housing and a diaphragm secured at its periphery to saidhousing and deformable in said.

diaphragm housing to effect displacement of fluid in the latter, I

(b) supply means communicating with the interior of said housing for conducting fluid to be pumped to said housing, i

(c) discharge means communicating with the interior of said housing for conducting pumped fluid fromv said housing,

(d) a fluid actuated means supported for reciprocative movement and connected to said diaphragm to deform the latter in said diaphragm housing,

(e) a fluid pump for producing fluid under pressure,

(7) passage means for conducting pressurized fluid from said fluid pump to said fluid actuated means,

(g) fluid flow control means responsive to fluid pressure for actuation from one position to another and associated With said passage means for controlling flow of pressurized fluid to said fluid actuated means so that the latter reciprocates and causes said diaphragm to be actuated to alternately draw fluid to be pumpedinto said diaphragm housing and discharge fluid from the diaphragm housing,

(h) means forming afluid chamber,

e (i) passage means communicating with said fluid chamher and said control means, and

(j) piston means disposed for slidable movement in said fluid chamber. and for'engagement with said fluid actuating means and slidable movement to compres s the fluid in said fluid chamber and thereby effect actuationof the control means from: said one position to another. 5 3. A fluid pump having at least one fluid displacement mean disposed Within a housing to divide the interior of the latter into at least one working chamber which communicates with a source of fluid to be pumped to receive such fluid therein and with apoint of use ofpumped fluid to pass purnp'ed fluid therefrom, in combination with a fluid actuating means comprising, i l

(a) means forming a pistoncharnber disposed adjacent said housing, p (b) a piston disposed for reciprocation within said piston chamber and connected to said fluid displacement means,

' (g); passage; means 'for safety device is providedbetweensaid supplyand return.

r i i (cv)'a fluid pumpforproviding afluid under-pressure,

(d) conduit means communicating With said fluid pump to receive pressurized fluid and with the piston cham- 'bervto conduct pressurized fluid to the opposite end portions of said piston chamber,

y (e) control means responsive to fluid pressure for actuationfrom-one position toanother and associated withsaid conduitmeans for'providingalternate flow ,of pressurizedfluidto' the opposite end portions of the piston chamber to cause reciprocation of said piston and therebyactuation' of the fluid displacement means and the pumping of fluid to be pumped, (f); means defining a fluid chamber adjacent each opposite end portion-of the piston chamber,

(g) pas age means communicating each of said fluid chambers with said control means, and

(h) a plunger means disposed in each of said fluid chambers: for slidable movement therein and engageable by said piston adjacent theend'of the pistons path of reciprocationto be slid and to compress fluid in Isaid'chamber and thereby effect actuation of said controlmeans from said one position to another.

4. A fluid pump having at least one diaphragm disposed Within a housing to divide the interior of the latter into at least; one workingchamber which; communicates with a source'o'f fluid to be pumped toreceive such fluid therein and vvith-apointofuse of pumped fluid to pass pumped fluid therefrom upon actuation of the diaphragm in combination with a fluidactuating means comprising,

(a) a fluid motor disposed adjacent the diaphragm housing and having a piston constructed and'arranged forreciprocation; c0nnected to saiddiaphragm,

(b) a fluidpurnp for providing fluid under'pressure,

(0) supply conduit means communicating the fluid pump with said fluid' motor to conduct pressurized fluid tothe latter on Opposite sides of said piston,

(d) return conduit means communicating the fluid pinup-with said fluid motorron opposite sides of said piston to return spent pressurized fluid to said fluid pump,

(e) control means responsive to fluid pressure for actuation-from one,,position to: another and associated with saidsupply, conduit means and said return conduit means to control flow of fluid through the supply and return :conduit means to eiiect reciprocation of said'piston andthereby actuation of the diaphragm to cause fluid to be purnped'tohe drawn into said diaphragm, housing and such'fluid tobe discharged therefrom to the point of use, I, V

(f) meansdefininga fluid chamber in said fluid motor at opposite ends of the path of'reciproc'ation of said .1 piston, I, a I

communicating each of said fluid chambers with1said control means and said fluid chamber, and I (h) Larplu ngerimeans disposed in each of said} fluid chambers for slidable 'movement therein and engageable by said piston near the end of the piston path of reciprocation to he slid and to compress fluid in said; cha-mber and thereby"etfectfactuation of said control means' from said onegposition to another.

The'combination as defined in claim 4 vs'rherein a 'cond uit rneans to provide for-by-passing pressurized fluid aroundsaidfluid motor when the pressurizedifluid attains apredetermined excesspressure. 1 6. A fluidfactuating meansof the character described re; a diaphragm pumphaving at least one diaphragm comprising I v (aJmeans deflninga piston chamber disposed adjacent said diaphragm pump, I v (b) atpiston disposed for reciprocation in said piston chamber and ha'ving a ipistonrod-connected to the diaphragm of said diaphragm pump,

(c) a closed cycle fluid pump for pressurizing fluid and having a fluid inlet and outlet,

(d drive means connected to said fluid pump to drive the latter,

(e) conduit means communicating the fluid outlet of said'fluid pump With the opposite ends of the piston chamber to deliver pressurized fluid to the latter,

(f) said conduitmean including return conduit means communicating the opposite ends of the piston chamber with the inlet of said fluid pump to conduct spent pressurized fluid from the piston chamber to the inlet of the fluid pump,

(g) control valve means responsive to pressurized fluid for actuation from one position to another disposed in said conduit means for providing alternate flow 0t fluid to the opposite ends of said piston chamber through said conduit means and alternate flow of fluid from the opposite ends of said piston chamber through said conduit means to thereby eflect reciprocation of the pistonand actuation of the diaphragm to pump fluid,

(11) means defining a fluid chamber adjacent each opposite end portion of said piston chamber,

(i) passage means communicating each of said fluid chambers With said control means, and

(j) a plunger means disposed in each of said fluid chambers for slidable movement therein and engageable by said piston adjacent the end of the pistons path of reciprocation to be slid and to compress fluid in said chamber and thereby etiect actuation of said control valve means from said one position to anotherx 7. A fluid actuating means of the character described for a diaphragm pump having at least one diaphragm comprising (a) housing means defining a piston chamber disposed adjacent the diaphragm pump,

(12) a piston disposed for reciprocation in said piston chamber and having a connecting rod connected to the diaphragm pump to effect actuation of the diaphragm upon reciprocation of the piston,

(c) a hydraulic pump for pressurizing a liquid,

(d) drive means connected to said hydraulic pump,

(e) conduit means communicating the hydraulic pump With the opposite ends of the piston chamber to conduct pressurized liquid to the latter,

(1) return conduit means communicating the hydraulic pump With the opposite ends of the piston chamber to conduct spent pressurized liquid from the latter to the hydraulic pump,

(g) a control valve disposed to control flow of liquid through said conduit means and return conduit means to provide in one position flow of pressurized fluid from the hydraulic pump, through the conduit meansto one end of the piston chamber and permit spent pressurized liquid to flow from the other end of the piston chamber through the return conduit means, to the hydraulic pump, and in another position provide flow of pressurized liquid and spent pressurized liquid to and from the piston chamber opposite from the said one position so as to cause reciprocation of the piston and actuation of the diaphragm of the diaphragm pump,

(11) said control valve having hydraulic actuated means for effecting movement of the control valve from one position to another,

(1) a hydraulic piston disposed in opposite ends of said piston chamber for slidable movement,

(j) said hydraulic piston being disposed to be engaged by said piston at the latter part of the stroke of said piston and moved to compress a liquid, and

(k)=passageway means for each of said pistons for conveying said compressed liquid to the hydraulic responsive means of the control varve to effect actuation of the lattertfrom one position to the other.

8. A fluid pump comprising (a) a pair of diaphragm pump sub-assemblies,

(b) each diaphragm pump sub-assembly comprising,

(1) a housing,

(2) a diaphragm disposed Within said housing to divide the interior of said housing into at least one working chamber,

(3) supply means communicating with the working chamber for passing fluid to be pumped therein,

(4) discharge means communicating with the Working chamber to pass fluid out of the working chamber upon movement of said diaphragm in the working chamber,

() means forming a piston chamber disposed between said diaphragm pump sub-assemblies,

(d) a piston disposed for reciprocation within said piston chamber and connected to the diaphragms of each of the diaphragm pump sub-assemblies,

(e) a fluid pump for providing a fluid under pressure,

(1) conduit means communicating with said fluid pump to receive pressurized fluid and with the piston chamber to conduct pressurized fluid to the opposite end portions of said piston chamber,

(g) exhaust means communicating with the opposite end portions of the piston chamber to permit flow of spent pressurized fluid from the piston chamber,

(h) control means responsive to pressurized fluid for actuation from one position to another and associated with said conduit means and said exhaust means for providing alternate flow of pressurized fluid to the opposite end portions of the piston chamber and alternate flow of spent pressurized fluid from the opposite end portions of the piston chamber to cause reciprocation of the piston and thereby actuation of each of the diaphragms of the diaphragm pump sub-assemblies and the pumping of fluid,

(i) means forming a fluid chamber adjacent each end portion of said piston chamber,

(j) a piston means disposed in each of said fluid chambers for slidable movement therein and engageable by said piston near the latter part of the piston stroke to compress the fluid therein, and

(k) passage means communicating each of said fluid chambers with the control means to pass compressed fluid to the latter and thereby eflect actuation of the control means from said one position to another.

9. The apparatus of claim 8 wherein a safety device is cooperatively associated with the conduit means to cause pressurized fluid to by-pass said piston chamber in response to a predetermined excess pressure of said pressurized fluid in said conduit means.

10. A fluid pump having at least .one diaphragm disposed within a housing to divide the interior of the latter into at least one Working chamber which comrnunieates with a source of fluid to be pumped to receive such fluid therein and with a point of use of pumped fluid to pass pumped fluid therefrom in combination with a fluid actuating means comprising (a) means forming a piston chamber disposed adjacent said housing, (11) a piston disposed for reciprocation within said piston chamber and connected to said diaphragmto eifect actuation of the latter,

(c) fluid supply means for providing fluid under pressure,

(d) conduit means communicating with said fluid supply means to receive pressurized fluid and with the piston chamber to conduct pressurized fluid to opposite end portions of the piston chamber,

(e) control means responsive to fluid pressure for actu-ation from one posit-ion to another and associated with said conduit means for providing alternate flow of pressurized fluid to the opposite end portions of the piston chamber to cause reciprocation of said piston and thereby actuation of the diaphragm and the pumping of fluid to be pumped,

(f) wall means disposed at opposite ends of said piston chamber having a bore therein,

(g) a plunger slidably disposed in each of said bore and defining with said bore a fluid chamber,

(h) each of said plungers being disposed to be engaged by said piston during the latter part of the stroke of said piston to be slid in said bore and thereby to compress the fluid within said fluid chamher, and

(i) passage means communicating at one end with said fluid chamber and at the opposite end with said control means to transmit pressurized fluid to the latter so as to cause the control means to be actuated from said one position to another.

References Cited by the Examiner UNITED STATES PATENTS 2,625,886 1/53 Browne 103-152 X 2,680,411 6/54 Hein 103-152 2,684,692 7/ 54 Hunter et a1.

2,751,144 6/56 Troendle 230-52 2,845,033 7/58 Wright 103-150 3,025,550 3/62 'Molenaar 103-150 X 3,039,399 6/62 Everett 103-150 3,068,795 12/62 Lauck 103-42 X 3,070,023 12/62 Glasgow 103-51 LAURENCE V. EFNER, Primary Examiner. JOSEPH H. BRANSON, 111., Examiner. 

1. A PUMP COMPRISING (A) AT LEAST ONE PUMPING MEANS INCLUDING A HOUSING AND A FLUID DISPLACEMENT MEANS DISPOSED FOR ACTUATION IN SAID HOUSING, (B) SUPPLY MEANS COMMUNICATING WITH THE INTERIOR OF SAID HOUSING FOR CONDUCTING FLUID TO BE PUMPED TO SAID HOUSING, (C) DISCHARGE MEANS COMMUNICATING WITH THE INTERIOR OF SAID HOUSING FOR CONDUCTING PUMPED FLUID OUT OF SAID HOUSING, AND (D) FLUID ACTUATING MEANS FOR ACTUATING SAID FLUID DISPLACEMENT MEANS WITHIN SAID HOUSING TO CAUSE FLUID TO BE DRAWN INTO SAID HOUSING THROUGH SAID SUPPLY MEANS AND TO FORCE FLUID FROM SAID HOUSING THROUGH SAID DISCHARGE MEANS, (E) SAID FLUID ACTUATING MEANS INCLUDING (1) A FLUID PUMP TO PROVIDE FLUID UNDER PRESSURE, (2) A CONTROL MEANS RESPONSIVE TO FLUID PRESSURE FOR ACTUATION FROM ONE POSITION TO ANOTHER FOR CONTROLLING FLOW OF FLUID UNDER PRESSURE SO AS TO EFFECT ACTUATING OF SAID FLUID DISPLACEMENT MEANS AND THEREBY ALTERNATELY DRAW FLUID TO BE PUMPED INTO SAID HOUSING AND DISCHARGE SAID FLUID FROM THE HOUSING, (3) MEANS FORMING A FLUID CHAMBER, (4) PASSAGE MEANS COMMUNICATING SAID FLUID CHAMBER WITH SAID CONTROL MEANS, AND (5) PISTON MEANS DISPOSED FOR SLIDABLE MOVEMENT IN SAID FLUID CHAMBER AND FOR ENGAGEMENT WITH SAID FLUID ACTUATING MEANS AND SLIDABLE MOVEMENT TO COMPRESS THE FLUID IN SAID FLUID CHAMBER AND THEREBY EFFECT ACTUATION OF THE CONTROL MEANS FROM SAID ONE POSITION TO ANOTHER. 